I had a slab I worked on that was poured with a very high ratio, I'd have to get the old papers out to see how high it was, but it was wet, like .65 or more.

It dried really quickly, much faster than any of us figured it would. Then we thought perhaps it was all the voids that helped it dry. There may be something to that, but the concrete was pretty weak. Good enough for a floor slab though.

Self-compacting concrete is a concrete mixture that is able to consolidate under its own weight. The highly fluid nature of it makes suitable for placing in difficult conditions and congested reinforcement. Use of it can also help minimize hearing-related damages on the worksite that are induced by vibration of concrete. Another advantage of Self-compacting concrete is that the time required to place large sections is considerably reduced. Self-consolidating concrete is a highly flowable, non-segregating concrete. It can be used casting heavily reinforced sections. The required level of fluidity is greatly influenced by the particular application under consideration. Obviously the most congested structural members demand the highest fluidity.

So when you use a self consolidating concrete there must be a stricter limit on the height of each pour. How long does the concrete take before it can support its own weight and then another lift above?

walked into a job today with 10" Cast in Place on Grade and Suspended
the concrete contractor told me they used Super P - there are a bunch of what looks like stress cracks throughout the slab - he told me that's common with this product - hoping you could shed some insight